Described below is a synchronous machine, containing a stator winding and a rotor inductance, with an excitation device for driving and monitoring the rotor inductance.
Specific excitation devices are provided for synchronous machines for use as electrical generators or motors. In particular in the case of machines with superconducting exciter windings, in which the current needs to be built up and reduced in a targeted manner, excitation devices including inverters, transformers and synchronous rectifiers are suitable, as are described, for example, in parallel applications by the Applicant with the same priority.
The installation site of such an excitation device should be as close as possible to the rotor inductance in order to minimize the losses on feed lines. In particular in the case of such superconducting windings which are constructed using HTS (high-temperature superconducting) technology, protection for the superconducting rotor inductance needs to be implemented which should be fitted as close as possible to the superconducting inductance in order to rule out the probability of breakage of the cable and the associated destruction of the superconducting rotor inductance or to keep this probability as low as possible.
The magnetic field produced by the currents in the winding head, on the one hand, and the stator and rotor stray field emerging from the air gap, on the other hand, are problematic for the latter excitation device. These undesirable magnetic fields can disrupt electronics located there and in particular bring the ferromagnetic materials of the transformer to saturation and therefore render them functionless.
An aspect of the synchronous machine is to use the available space below the stator winding head as the installation site for contactless energy and data transmission without introducing faults. In particular, it should in this case equally be possible to use a special protection concept for an advantageous use of HTS coils on the rotor.